diff --git a/sdk_container/src/third_party/coreos-overlay/coreos/config/make.conf.amd64-target b/sdk_container/src/third_party/coreos-overlay/coreos/config/make.conf.amd64-target
index 8de75eb292..4b64c069c6 100644
--- a/sdk_container/src/third_party/coreos-overlay/coreos/config/make.conf.amd64-target
+++ b/sdk_container/src/third_party/coreos-overlay/coreos/config/make.conf.amd64-target
@@ -8,12 +8,5 @@ source make.conf.board_setup
 # Common settings across all board targets.
 source make.conf.common
 
-# Recommended MARCH_TUNE, CFLAGS, etc.
-MARCH_TUNE=""
-
-# Allow a board to override or define additional settings.
-CFLAGS="-O2 -pipe ${MARCH_TUNE} -g"
-CXXFLAGS="${CFLAGS}"
-
 # Allow the user to override or define additional settings.
 source make.conf.user
diff --git a/sdk_container/src/third_party/coreos-overlay/profiles/coreos/amd64/generic/make.defaults b/sdk_container/src/third_party/coreos-overlay/profiles/coreos/amd64/generic/make.defaults
new file mode 100644
index 0000000000..254f8753a5
--- /dev/null
+++ b/sdk_container/src/third_party/coreos-overlay/profiles/coreos/amd64/generic/make.defaults
@@ -0,0 +1,3 @@
+# Enable optimizations for common x86_64 CPUs
+CFLAGS="-O2 -pipe -mtune=generic"
+CXXFLAGS="${CFLAGS}"
diff --git a/sdk_container/src/third_party/coreos-overlay/profiles/coreos/amd64/sdk/make.defaults b/sdk_container/src/third_party/coreos-overlay/profiles/coreos/amd64/sdk/make.defaults
new file mode 100644
index 0000000000..254f8753a5
--- /dev/null
+++ b/sdk_container/src/third_party/coreos-overlay/profiles/coreos/amd64/sdk/make.defaults
@@ -0,0 +1,3 @@
+# Enable optimizations for common x86_64 CPUs
+CFLAGS="-O2 -pipe -mtune=generic"
+CXXFLAGS="${CFLAGS}"